On Tue, Dec 09, 2025 at 04:15:25PM +0530, Mukesh Ojha wrote:
> On Mon, Dec 08, 2025 at 10:19:26PM +0530, Mukesh Ojha wrote:
> > On Fri, Dec 05, 2025 at 04:40:51PM -0600, Bjorn Andersson wrote:
> > > On Fri, Nov 21, 2025 at 04:31:13PM +0530, Mukesh Ojha wrote:
[..]
> > >
> > > Wouldn't be unreasonable to return an ERR_PTR() with the allocated
> > > buffer, instead of returning through the reference.
> >
> > We anyway have to return the size through reference, why not do the same
> > for
> > allocated buffer as well..
>
>
> Tried to take care most of the comments apart from above one., let me know if
> below is fine..
It's indeed fine, much better. Thank you.
>
> ---------------------------------------o<---------------------------------------
>
> diff --git a/drivers/firmware/qcom/qcom_scm.c
> b/drivers/firmware/qcom/qcom_scm.c
> index 4ce892d8fb25..a589961f8225 100644
> --- a/drivers/firmware/qcom/qcom_scm.c
> +++ b/drivers/firmware/qcom/qcom_scm.c
> @@ -27,6 +27,7 @@
> #include <linux/of_reserved_mem.h>
> #include <linux/platform_device.h>
> #include <linux/reset-controller.h>
> +#include <linux/remoteproc.h>
> #include <linux/sizes.h>
> #include <linux/types.h>
>
> @@ -111,6 +112,10 @@ enum qcom_scm_qseecom_tz_cmd_info {
> QSEECOM_TZ_CMD_INFO_VERSION = 3,
> };
>
> +enum qcom_scm_rsctable_resp_type {
> + RSCTABLE_BUFFER_NOT_SUFFICIENT = 20,
This isn't an enumeration, it's the constant 20. So #define would be
more suitable...
> +};
> +
> #define QSEECOM_MAX_APP_NAME_SIZE 64
> #define SHMBRIDGE_RESULT_NOTSUPP 4
>
> @@ -766,6 +771,171 @@ int qcom_scm_pas_mem_setup(u32 pas_id, phys_addr_t
> addr, phys_addr_t size)
> }
> EXPORT_SYMBOL_GPL(qcom_scm_pas_mem_setup);
>
> +static int __qcom_scm_pas_get_rsc_table(u32 pas_id, void *input_rt,
> + size_t input_rt_size, void *output_rt,
> + size_t *output_rt_size)
> +{
> + struct qcom_scm_desc desc = {
> + .svc = QCOM_SCM_SVC_PIL,
> + .cmd = QCOM_SCM_PIL_PAS_GET_RSCTABLE,
> + .arginfo = QCOM_SCM_ARGS(5, QCOM_SCM_VAL, QCOM_SCM_RO,
> QCOM_SCM_VAL,
> + QCOM_SCM_RW, QCOM_SCM_VAL),
> + .args[0] = pas_id,
> + .owner = ARM_SMCCC_OWNER_SIP,
> + };
> + struct qcom_scm_res res;
> + int ret;
> +
> + desc.args[1] = qcom_tzmem_to_phys(input_rt);
> + desc.args[2] = input_rt_size;
> + desc.args[3] = qcom_tzmem_to_phys(output_rt);
> + desc.args[4] = *output_rt_size;
> +
> + /*
> + * Whether SMC fail or pass, res.result[2] will hold actual resource
> table
> + * size.
> + *
> + * If passed 'output_rt_size' buffer size is not sufficient to hold the
> + * resource table TrustZone sends, response code in res.result[1] as
> + * RSCTABLE_BUFFER_NOT_SUFFICIENT so that caller can retry this SMC call
> + * with output_rt buffer with res.result[2] size however, It should not
> + * be of unresonable size.
> + */
> + ret = qcom_scm_call(__scm->dev, &desc, &res);
> + if (res.result[2] > SZ_1G) {
> + ret = -E2BIG;
> + return ret;
> + }
> +
> + *output_rt_size = res.result[2];
> + if (ret && res.result[1] == RSCTABLE_BUFFER_NOT_SUFFICIENT)
> + ret = -EOVERFLOW;
> +
> + return ret ? : res.result[0];
> +}
> +
> +/**
> + * qcom_scm_pas_get_rsc_table() - Retrieve the resource table in passed
> output buffer
> + * for a given peripheral.
> + *
> + * Qualcomm remote processor may rely on both static and dynamic resources
> for
> + * its functionality. Static resources typically refer to memory-mapped
> addresses
> + * required by the subsystem and are often embedded within the firmware
> binary
> + * and dynamic resources, such as shared memory in DDR etc., are determined
> at
> + * runtime during the boot process.
> + *
> + * On Qualcomm Technologies devices, it's possible that static resources are
> not
> + * embedded in the firmware binary and instead are provided by TrustZone
> However,
> + * dynamic resources are always expected to come from TrustZone. This
> indicates
> + * that for Qualcomm devices, all resources (static and dynamic) will be
> provided
> + * by TrustZone via the SMC call.
> + *
> + * If the remote processor firmware binary does contain static resources,
> they
> + * should be passed in input_rt. These will be forwarded to TrustZone for
> + * authentication. TrustZone will then append the dynamic resources and
> return
> + * the complete resource table in output_rt.
> + *
> + * If the remote processor firmware binary does not include a resource table,
> + * the caller of this function should set input_rt as NULL and input_rt_size
> + * as zero respectively.
> + *
> + * More about documentation on resource table data structures can be found in
> + * include/linux/remoteproc.h
> + *
> + * @ctx: PAS context
> + * @pas_id: peripheral authentication service id
> + * @input_rt: resource table buffer which is present in firmware binary
> + * @input_rt_size: size of the resource table present in firmware binary
> + * @output_rt: buffer to which the both static and dynamic
> resources will
> + * be returned.
> + * @output_rt_size: TrustZone expects caller should pass worst case size for
> + * the output_rt.
> + *
> + * Return: 0 on success and nonzero on failure.
> + *
> + * Upon successful return, output_rt will have the resource table and
> output_rt_size
> + * will have actual resource table size,
> + */
> +int qcom_scm_pas_get_rsc_table(struct qcom_scm_pas_context *ctx, void
> *input_rt,
> + size_t input_rt_size, void **output_rt,
> + size_t *output_rt_size)
> +{
> + struct resource_table empty_rsc = {};
> + size_t size = SZ_16K;
> + void *output_rt_tzm;
> + void *input_rt_tzm;
> + int ret;
> +
> + ret = qcom_scm_clk_enable();
> + if (ret)
> + return ret;
> +
> + ret = qcom_scm_bw_enable();
> + if (ret)
> + goto disable_clk;
> +
> + /*
> + * TrustZone can not accept buffer as NULL value as argument Hence,
Lowercase 'h' in Hence, please.
> + * we need to pass a input buffer indicating that subsystem firmware
> + * does not have resource table by filling resource table structure.
> + */
> + if (!input_rt) {
> + input_rt = &empty_rsc;
> + input_rt_size = sizeof(empty_rsc);
> + }
> +
> + input_rt_tzm = qcom_tzmem_alloc(__scm->mempool, input_rt_size,
> GFP_KERNEL);
> + if (!input_rt_tzm) {
> + ret = -ENOMEM;
> + goto disable_scm_bw;
> + }
> +
> + memcpy(input_rt_tzm, input_rt, input_rt_size);
> +
> + do {
> + output_rt_tzm = qcom_tzmem_alloc(__scm->mempool, size,
> GFP_KERNEL);
> + if (!output_rt_tzm) {
> + ret = -ENOMEM;
> + goto free_input_rt;
> + }
> +
> + ret = __qcom_scm_pas_get_rsc_table(ctx->pas_id, input_rt_tzm,
> + input_rt_size, output_rt_tzm,
> + &size);
> + if (ret)
> + qcom_tzmem_free(output_rt_tzm);
> +
> + } while (ret == -EOVERFLOW);
> +
> + if (!ret) {
> + void *tbl_ptr;
> +
> + tbl_ptr = kzalloc(size, GFP_KERNEL);
> + if (!tbl_ptr)
> + goto free_output_rt;
> +
> + memcpy(tbl_ptr, output_rt_tzm, size);
> + *output_rt = tbl_ptr;
> + *output_rt_size = size;
> + }
> +
> +free_output_rt:
> + if (!ret)
> + qcom_tzmem_free(output_rt_tzm);
> +
> +free_input_rt:
> + qcom_tzmem_free(input_rt_tzm);
> +
> +disable_scm_bw:
> + qcom_scm_bw_disable();
> +
> +disable_clk:
> + qcom_scm_clk_disable();
> +
> + return ret;
I still think it would be nice to match the prototype of
rproc_find_loaded_rsc_table() and return the pointer our resource table.
Effectively:
return ret ? ERR_PTR(ret) : tbl_ptr;
(although return tbl_ptr; after making sure it's either the allocated
memory or ERR_PTR() would be nicer)
Should be able to make the return type struct resource_table * (even
though struct resource_table is a opaque type here).
But, my concrete concerns have been addressed, so I'm happy either way.
Regards,
Bjorn
> +}
> +EXPORT_SYMBOL_GPL(qcom_scm_pas_get_rsc_table);
> +
> /**
> * qcom_scm_pas_auth_and_reset() - Authenticate the given peripheral firmware
> * and reset the remote processor
> diff --git a/drivers/firmware/qcom/qcom_scm.h
> b/drivers/firmware/qcom/qcom_scm.h
> index a56c8212cc0c..50d87c628d78 100644
> --- a/drivers/firmware/qcom/qcom_scm.h
> +++ b/drivers/firmware/qcom/qcom_scm.h
> @@ -105,6 +105,7 @@ int qcom_scm_shm_bridge_enable(struct device *scm_dev);
> #define QCOM_SCM_PIL_PAS_SHUTDOWN 0x06
> #define QCOM_SCM_PIL_PAS_IS_SUPPORTED 0x07
> #define QCOM_SCM_PIL_PAS_MSS_RESET 0x0a
> +#define QCOM_SCM_PIL_PAS_GET_RSCTABLE 0x21
>
> #define QCOM_SCM_SVC_IO 0x05
> #define QCOM_SCM_IO_READ 0x01
> diff --git a/include/linux/firmware/qcom/qcom_scm.h
> b/include/linux/firmware/qcom/qcom_scm.h
> index d6d83888bb75..7c331598ea15 100644
> --- a/include/linux/firmware/qcom/qcom_scm.h
> +++ b/include/linux/firmware/qcom/qcom_scm.h
> @@ -88,6 +88,10 @@ int qcom_scm_pas_mem_setup(u32 pas_id, phys_addr_t addr,
> phys_addr_t size);
> int qcom_scm_pas_auth_and_reset(u32 pas_id);
> int qcom_scm_pas_shutdown(u32 pas_id);
> bool qcom_scm_pas_supported(u32 pas_id);
> +int qcom_scm_pas_get_rsc_table(struct qcom_scm_pas_context *ctx, void
> *input_rt,
> + size_t input_rt_size, void **output_rt,
> + size_t *output_rt_size);
> +
>
>
> >
> >
> > --
> > -Mukesh Ojha
>
> --
> -Mukesh Ojha
